Time for action – using STL containers

Let's now replace raw arrays with standard STL containers by following these steps:

1. Open the jni/GraphicsManager.hpp header and include the headers:
   • Vector, which defines an STL container encapsulating C arrays (with a few more interesting features such as dynamic resizing)
   • Map, which encapsulates the equivalent of a Java HashMap (that is, an associative array)

   Then, remove the textureResource member in the TextureProperties structure. Use a map container instead of a raw array for mTextures (prefixed with the std namespace). The first parameter is the key type and the second the value type.

   Finally, replace all the other raw arrays with a vector, as shown in the following:

   ...
   #include <android_native_app_glue.h>
   #include <GLES2/gl2.h>
   #include <EGL/egl.h>
   
   #include <map>
   #include <vector>
   ...
   struct TextureProperties {
       GLuint texture;
       int32_t width;
       int32_t height;
   };
   
   class GraphicsManager {
       ....